Open AccessEvidence for syntrophic butyrate metabolism under sulfate‐reducing conditions in a hydrocarbon‐contaminated aquifer
Author(s) -
Struchtemeyer Christopher G.,
Duncan Kathleen E.,
McInerney Michael J.
Publication year - 2011
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2011.01046.x
Subject(s) - sulfate , butyrate , microcosm , methanogenesis , environmental chemistry , halomonas , sulfate reducing bacteria , biology , hydrocarbon , propionate , biochemistry , chemistry , methane , fermentation , ecology , organic chemistry , 16s ribosomal rna , gene
The importance of syntrophy in the degradation of butyrate in an aquifer where sulfate reduction was shown to be an important terminal electron‐accepting process was assessed. Hydrocarbon‐contaminated aquifer sediments coupled butyrate degradation to sulfate reduction and methane production. Butyrate degradation in methanogenic microcosms was inhibited by the addition of 2‐bromoethanesulfonic acid, and was restored by the addition of 10 mM sulfate and a hydrogen‐ and formate‐using sulfate reducer, but not by the addition of 10 mM sulfate alone. Molybdate addition inhibited butyrate degradation in sulfate‐reducing microcosms. The addition of CO, which inhibits hydrogenases, to sulfate‐reducing microcosms inhibited butyrate metabolism and caused the hydrogen partial pressure to increase to levels that would make syntrophic butyrate degradation via sulfate reduction energetically unfavorable (−5 to +3 kJ mol −1 ). DNA extracted from the most probable number cultures and contaminated sediments contained sequences related to members of the families Syntrophomonadaceae and Syntrophaceae , whose members are known to syntrophically degrade fatty acids, as well as sequences related to uncultured Firmicutes, Desulfobulbaceae, Desulfobacteriaceae , and Desulfovibrionaceae . These data show that contaminated sediments degraded butyrate syntrophically coupled to methane production and sulfate reduction.